I use a flatiron but if I had to choose between a stove pressing comb and an electric comb, I'd go for the electric. I'd feel safer using it because I can keep the temperature constant. It takes ONE wrong move (like a temperature too high) to singe your hair and lose it. Better safe than sorry.
But so you don't waste your time with one that won't give you good results, I'd ask folks who use electric pressing combs to recommend one that has a good enough temperature.